The present invention relates to a load port device that is disposed in front of a processing device for performing a wafer processing and that carries out an opening/closing operation of a cover of a wafer carrier and a sending/receiving operation of a wafer housed in the wafer carrier in a semiconductor fabrication apparatus.
Referring to the drawings according to the invention, first, a semiconductor fabrication apparatus (hereinafter, simply referred to as “a fabrication apparatus”) and a front-end apparatus (hereinafter, referred to as “an EFEM”) will be described, and subsequently a related-art load port device will be described. FIG. 7 is a longitudinal sectional view illustrating a fabrication apparatus. FIG. 9 is an overall perspective view illustrating a related-art load port device F′. In a semiconductor fabrication factory, a carrier conveyance system conveys a plurality of wafers W housed in a wafer carrier (hereinafter, simply referred to as “a carrier”) 30 to facilities in production lines by a carrier unit. FOUP (Front Opening Unified Pod) is frequently used as the carrier. As shown in FIG. 7, a fabrication apparatus for receiving the wafer W by a carrier unit and performing a wafer processing includes the EFEM having a stockyard R1, and a processing device R3. The EFEM which includes an external load port L, the stockyard processing device R3. The EFEM which includes an external load port L, the stockyard R1 and an enclosure R2 is installed on the front side of the processing device R3. The carrier 30 that is conveyed from the carrier conveyance system and to be transferred to the stockyard R1 of the fabrication apparatus is placed on the external load port L. As shown in FIG. 7, the external load port L is placed outside the stock yard R1. In the stockyard R1, a plurality of carrier installation shelves S on which the carrier 30 is placed and a carrier transfer device T1 are disposed. Further, the enclosure R2 is a front chamber of the processing device R3. An FFU (Fan Filter Unit) and a wafer conveyance robot T2 are provided in the enclosure R2. In the enclosure R2, highly clean air is sent out by the FFU. Thus, the wafer W is prevented from being contaminated with particles before a wafer processing.
In the fabrication apparatus, the related-art load port device F′ is an internal load port device that is mounted in the front side of a wall member P by means of a bolt 81 or the like, which isolates the stockyard R1 from the enclosure R2 that is a front chamber of the processing device R3. Hereinafter, the internal load port device will be called “a load port device” and distinguished from the external load port L. As shown in FIG. 9, the related-art load port device F′ includes a mount base 1 that has a rectangular plate shape and is mounted on the wall member P, a wafer transfer window 2 that is provided on the mount base 1, and a carrier stage C that is disposed on a substantial lower end of the wafer transfer window 2 and places the carrier 30 thereon. The carrier stage C is disposed so as to be parallel to the stockyard R1 that is in a front side of the wall member P, and the front side is a front side of the load port device F′. In the same front side, an elevation mechanism U2 of a mapping device M for detecting an existence or non-existence of the wafer W housed in the carrier 30 in each stair is disposed below one side of the carrier stage C. The rear side of the load port device F′ is disposed in the enclosure R2. In the same rear side, a cover opening/closing unit N for carrying out an opening/closing operation of a cover 32 of the carrier 30 by detaching and attaching the cover 32 therefrom and thereto, an elevation mechanism U1 of the cover opening/closing unit N, and the mapping device M are disposed. Further, a support member 1a is attached to both ends of the mount base 1.
When the carrier 30 housing the wafer W is conveyed to the fabrication apparatus, the carrier 30 is received in the external load port L and then temporarily stored in the stockyard R1 by the carrier transfer device T1. When a non-processed wafer W is supplied to the processing device R3 in accordance with a wafer processing status of the processing device R3, the carrier 30 stored in the stockyard R1 is first transferred onto a carrier plate 11 of the carrier stage C of the load port device F′ by the transfer device T1, and then the carrier plate 11 moves toward the wafer transfer window 2. Subsequently, the cover 32 of the carrier 30 is opened by the cover opening/closing unit N of the load port device F′ and then the wafer W in the carrier 30 is conveyed to the processing device R3 so as to perform a wafer processing thereon. After the wafer processing ends, the wafer W is again housed in the carrier 30 from the processing device R3, the cover 32 of the carrier 30 is closed, and then the carrier plate 11 moves away from the wafer transfer window 2. Subsequently, the carrier 30 is transferred from the carrier stage C to the external load port L or a carrier installation shelf S in the stockyard R1. The carrier 30 transferred to the external load port L is conveyed from the fabrication apparatus to proceed to the next process by the carrier conveyance system. The carrier 30 transferred to the carrier installation shelf S is also transferred to the external load port L at any time. Similarly, the carrier 30 is conveyed from the fabrication apparatus to proceed to the next process. The load port device F′ for carrying out a sending operation of the carrier 30 and a receiving operation of the carrier 30 at the same time and the carrier transfer device T1 are disclosed in Patent Document 1. In addition, a carrier interface device including an open/close mechanism of the carrier 30 is disclosed, for example, in Patent Document 2.
In a case where the wafer W is supplied to the processing device R3 in accordance with the wafer processing status of the processing device R3, it is more effective in terms of cost and time to supply the carrier 30 temporarily stored in the stockyard R1 from the stockyard R1 to the processing device R3 on demand than to supply the carrier 30 housing the wafer W from outside to the fabrication apparatus on demand. In order to improve an operation rate of the fabrication apparatus and to process a lot of wafer W, it is necessary to ensure storing spaces as many as the number of the wafers W or storing spaces for the carriers 30 housing the wafer W. However, since the fabrication apparatus is in a clean room, it is not possible to arbitrarily increase storing spaces for the wafer W within a limited space of the clean room. For this reason, in the past, it was a task to increase a reception capacity of the wafer W in the clean room, particularly in the stockyard R1, that is, a reception capacity of the carrier.
Patent Document 1: Japanese Patent Publication No. 2003-51527A
Patent Document 2: Japanese Patent Publication No. 10-303271A